1.\" $NetBSD: gzip.1,v 1.31 2018/10/26 22:10:15 christos Exp $ 2.\" 3.\" Copyright (c) 1997, 2003, 2004, 2008, 2009, 2015, 2017 Matthew R. Green 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 20.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 21.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 22.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 23.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.\" $FreeBSD$ 28.Dd January 7, 2019 29.Dt GZIP 1 30.Os 31.Sh NAME 32.Nm gzip , 33.Nm gunzip , 34.Nm zcat 35.Nd compression/decompression tool using Lempel-Ziv coding (LZ77) 36.Sh SYNOPSIS 37.Nm 38.Op Fl cdfhkLlNnqrtVv 39.Op Fl S Ar suffix 40.Ar file 41.Oo 42.Ar file Oo ... 43.Oc 44.Oc 45.Nm gunzip 46.Op Fl cfhkLNqrtVv 47.Op Fl S Ar suffix 48.Ar file 49.Oo 50.Ar file Oo ... 51.Oc 52.Oc 53.Nm zcat 54.Op Fl fhV 55.Ar file 56.Oo 57.Ar file Oo ... 58.Oc 59.Oc 60.Sh DESCRIPTION 61The 62.Nm 63program compresses and decompresses files using Lempel-Ziv coding 64(LZ77). 65If no 66.Ar files 67are specified, 68.Nm 69will compress from standard input, or decompress to standard output. 70When in compression mode, each 71.Ar file 72will be replaced with another file with the suffix, set by the 73.Fl S Ar suffix 74option, added, if possible. 75.Pp 76In decompression mode, each 77.Ar file 78will be checked for existence, as will the file with the suffix 79added. 80Each 81.Ar file 82argument must contain a separate complete archive; 83when multiple 84.Ar files 85are indicated, each is decompressed in turn. 86.Pp 87In the case of 88.Nm gzcat 89the resulting data is then concatenated in the manner of 90.Xr cat 1 . 91.Pp 92If invoked as 93.Nm gunzip 94then the 95.Fl d 96option is enabled. 97If invoked as 98.Nm zcat 99or 100.Nm gzcat 101then both the 102.Fl c 103and 104.Fl d 105options are enabled. 106.Pp 107This version of 108.Nm 109is also capable of decompressing files compressed using 110.Xr compress 1 , 111.Xr bzip2 1 , 112.Ar lzip , 113or 114.Xr xz 1 . 115.Sh OPTIONS 116The following options are available: 117.Bl -tag -width XXrXXXrecursiveX 118.It Fl 1 , Fl Fl fast 119.It Fl 2 , 3 , 4 , 5 , 6 , 7 , 8 120.It Fl 9 , Fl Fl best 121These options change the compression level used, with the 122.Fl 1 123option being the fastest, with less compression, and the 124.Fl 9 125option being the slowest, with optimal compression. 126The default compression level is 6. 127.It Fl c , Fl Fl stdout , Fl Fl to-stdout 128This option specifies that output will go to the standard output 129stream, leaving files intact. 130.It Fl d , Fl Fl decompress , Fl Fl uncompress 131This option selects decompression rather than compression. 132.It Fl f , Fl Fl force 133This option turns on force mode. 134This allows files with multiple links, symbolic links to regular files, 135overwriting of pre-existing files, reading from or writing to a terminal, 136and when combined with the 137.Fl c 138option, allowing non-compressed data to pass through unchanged. 139.It Fl h , Fl Fl help 140This option prints a usage summary and exits. 141.It Fl k , Fl Fl keep 142This option prevents 143.Nm 144from deleting input files after (de)compression. 145.It Fl L , -license 146This option prints 147.Nm 148license. 149.It Fl l , Fl Fl list 150This option displays information about the file's compressed and 151uncompressed size, ratio, uncompressed name. 152With the 153.Fl v 154option, it also displays the compression method, CRC, date and time 155embedded in the file. 156.It Fl N , Fl Fl name 157This option causes the stored filename in the input file to be used 158as the output file. 159.It Fl n , Fl Fl no-name 160This option stops the filename and timestamp from being stored in 161the output file. 162.It Fl q , Fl Fl quiet 163With this option, no warnings or errors are printed. 164.It Fl r , Fl Fl recursive 165This option is used to 166.Nm 167the files in a directory tree individually, using the 168.Xr fts 3 169library. 170.It Fl S Ar suffix , Fl Fl suffix Ar suffix 171This option changes the default suffix from .gz to 172.Ar suffix . 173.It Fl t , Fl Fl test 174This option will test compressed files for integrity. 175.It Fl V , Fl Fl version 176This option prints the version of the 177.Nm 178program. 179.It Fl v , Fl Fl verbose 180This option turns on verbose mode, which prints the compression 181ratio for each file compressed. 182.El 183.Sh ENVIRONMENT 184If the environment variable 185.Ev GZIP 186is set, it is parsed as a white-space separated list of options 187handled before any options on the command line. 188Options on the command line will override anything in 189.Ev GZIP . 190.Sh EXIT STATUS 191The 192.Nm 193utility exits 0 on success, 1941 on errors, 195and 2 if a warning occurs. 196.Sh SIGNALS 197.Nm 198responds to the following signals: 199.Bl -tag -width indent 200.It Dv SIGINFO 201Report progress to standard error. 202.El 203.Sh SEE ALSO 204.Xr bzip2 1 , 205.Xr compress 1 , 206.Xr xz 1 , 207.Xr fts 3 , 208.Xr zlib 3 209.Sh HISTORY 210The 211.Nm 212program was originally written by Jean-loup Gailly, licensed under 213the GNU Public Licence. 214Matthew R. Green wrote a simple front end for 215.Nx 1.3 216distribution media, based on the freely re-distributable zlib library. 217It was enhanced to be mostly feature-compatible with the original 218GNU 219.Nm 220program for 221.Nx 2.0 . 222.Pp 223This implementation of 224.Nm 225was ported based on the 226.Nx 227.Nm 228version 20181111, 229and first appeared in 230.Fx 7.0 . 231.Sh AUTHORS 232.An -nosplit 233This implementation of 234.Nm 235was written by 236.An Matthew R. Green Aq Mt mrg@eterna.com.au 237with unpack support written by 238.An Xin LI Aq Mt delphij@FreeBSD.org . 239.Sh BUGS 240According to RFC 1952, the recorded file size is stored in a 32-bit 241integer, therefore, it cannot represent files larger than 4GB. 242This limitation also applies to 243.Fl l 244option of 245.Nm 246utility. 247